Soil release agents are key ingredients in cleaning, e.g., textile laundry and hard surface such as carpet-cleaning; and textile treating. Soil release agents are commonly applied during manufacture of clothing or textile fiber. The primary purpose of the soil release agents is to make it easier to clean the textile fibers by home cleaning methods using conventional household machines or cleaners.
For example, in laundering processes normally employed, such as washing in a conventional home washing machine or hand washing with detergent bars, it is usually very difficult to remove soil and/or oily stains from textile material. Moreover, assuming that the undesirable materials are removed from the textile and/or a fairly clean textile material is being washed, soil remaining in the wash water is often redeposited onto the textile material prior to the end of the wash cycle. Hence, when the textile material is removed from the washing machine and subsequently dried, it has not been properly cleaned. Thus, textile material after use rarely assumes a truly clean appearance, but instead tends to gray and/or yellow due to the soil and/or oily materials deposited or redeposited and remaining thereon.
Also, synthetic fibers, and, therefore, fabrics having synthetic fibers incorporated therein or made entirely of synthetic fibers, are hydrophobic and oleophilic. Therefore, the oleophilic characteristics of the fiber permit oil and grime to be readily embedded in the fiber, and the hydrophobic properties of the fiber prevent water from entering the fiber to remove the contaminants from the fiber.
The purpose of a soil-release treatment is to help in the removal of soils during the cleaning of the item. Soil-release agents are typically added during textile manufacturing as a mill treatment. They are mostly applied to 100% polyester fabric via, padding (continuous or semi-continuous), or by exhaustion during dyeing and scouring. Generally, the polymer is fixed onto the fabric surface via a crosslinking agent or heat-setting (sorptive bonding). By design, these treatments are intended to be permanent.